feat(projects): Plan 5 Task 3 — store + StoreProjectRequest + ProjectService::create

- StoreProjectRequest: 3-way conditional validation (site domain regex, call 7\d{10}, sms senders required)
- ProjectService::create(): max_projects limit check via Tenant.limits JSONB + dispatch SyncSupplierProjectJob
- ProjectController: constructor DI + store() method returning 201
- SyncSupplierProjectJob: stub (Task 4 полная реализация)
- POST /api/projects route inside auth:sanctum+tenant group (name projects.store)
- Migration add_limits_to_tenants: JSONB DEFAULT '{}' per-tenant limits column
- Tenant model: limits added to fillable + casts as array
- schema.sql/CHANGELOG: tenants.limits documented in v8.20
- phpstan-baseline: +8 actingAs entries for new test file
- Quirk: region_mode in request uses 'include'/'exclude' (schema CHECK) not 'all'/'whitelist' (plan spec typo)
- Quirk: Project::first() → Project::where('signal_identifier','x.ru')->latest()->first() (no RefreshDatabase, persistent test DB)
- 8/8 ProjectsStoreTest passed; 699/706 total (4 pre-existing failures unchanged)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/app/Services/Project/ProjectService.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\Project;
+
+use App\Jobs\SyncSupplierProjectJob;
+use App\Models\Project;
+use App\Models\Tenant;
+use Illuminate\Http\Exceptions\HttpResponseException;
+
+class ProjectService
+{
+    public function create(Tenant $tenant, array $data): Project
+    {
+        $limit = (int) ($tenant->limits['max_projects'] ?? 10);
+        $current = Project::where('tenant_id', $tenant->id)->active()->count();
+        if ($current >= $limit) {
+            throw new HttpResponseException(response()->json([
+                'message' => "Достигнут лимит проектов ({$limit}). Смените тариф.",
+            ], 403));
+        }
+
+        $data['tenant_id'] = $tenant->id;
+        $data['is_active'] = true;
+        $project = Project::create($data);
+
+        SyncSupplierProjectJob::dispatch($project->id);
+
+        return $project->fresh();
+    }
+}